This invention relates to apparatus for transporting articles, comprising a closed track including rectilinear track portions containing carriers for carrying the articles, and drive means arranged to act on the respective rearmost ones of a series of successive carriers for sliding the carriers stepwise over the carrier track.
Prior apparatus of this type is disclosed in German patent 149306 as a filling and packaging machine comprising a rectangular track in which rectangular carriers circulate which each carry a plurality of articles. Series of successive carriers are arranged in both the long and the short legs of the carrier track. These series are periodically moved on a given distance along the carrier track by drive means which push against the rearmost one of a series of carriers.
When the carriers are stationary, the foremost one of a series is removed, which is effected by pushing such carrier to an adjacent different series. At the same time a carrier is added at the rear of the former series of carriers from a different series of carriers. Thereafter the entire series of carriers, now with fresh rearmost and foremost carriers is again advanced by one increment. When the series is stationary, the articles carried by the carriers can be subjected to a treatment by one or more stationary treating devices. In order that these treatments may be carried out without irregularities, it is necessary for the carrier with the articles being treated to occupy an accurate position relative to the treating device. As, however, the carriers of a series are not interconnected, minor relative displacements may arise between successive carriers as they are pushed on. As a result, when the series stops a carrier may not always occupy the correct position relative to a treating device. In the prior apparatus, misalignment of a carrier is corrected by inserting two fingers of a centering means into apertures of the carrier at the position of a treating device, which fingers push the carrier into the correct position.
In other respects, too, it is disadvantageous when the individual carriers of a series are not always properly closed-up. Thus collisions between the carriers will result in increased wear and tear of the carriers and the carrier track, and irregularities may occur as the series is pushed up by the drive means and as the foremost one of a series of carriers is pushed away to a different series. Treating the articles on the carriers during their movement becomes more difficult, too.